We got Oooma a few months ago and only wish we had known about it when we first moved up here in the mountains. Cell coverage is spotty at best.
They do sell a lot of bells and whistles to go with the basic box, including various services with monthly charges. All we wanted was a phone without anything else. We still have caller ID and voice mail, which we can check through the laptop anywhere in the world.
We just got a cordless phone and hooked things up. Very easy and simple. The only problem we may have is that we get our internet through them things flying up in the sky and we need power electrical power for everything. Cell phones are now used for backup, which we haven't need them for, or when on the road.
Believe we paid about $90 and pay $4.89 a month.